1 Commits

Author	SHA1	Message	Date
Steve Canny	d9f8467187	fix(xlsx): xlsx subtable algorithm (#2534) ... **Reviewers:** It may be easier to review each of the two commits separately. The first adds the new `_SubtableParser` object with its unit-tests and the second one uses that object to replace the flawed existing subtable-parsing algorithm. **Summary** There are a cluster of bugs in `partition_xlsx()` that all derive from flaws in the algorithm we use to detect "subtables". These are encountered when the user wants to get multiple document-elements from each worksheet, which is the default (argument `find_subtable = True`). This PR replaces the flawed existing algorithm with a `_SubtableParser` object that encapsulates all that logic and has thorough unit-tests. **Additional Context** This is a summary of the failure cases. There are a few other cases but they're closely related and this was enough evidence and scope for my purposes. This PR fixes all these bugs: ```python # # -- ✅ CASE 1: There are no leading or trailing single-cell rows. # -> this subtable functions never get called, subtable is emitted as the only element # # a b -> Table(a, b, c, d) # c d # -- ✅ CASE 2: There is exactly one leading single-cell row. # -> Leading single-cell row emitted as `Title` element, core-table properly identified. # # a -> [ Title(a), # b c Table(b, c, d, e) ] # d e # -- ❌ CASE 3: There are two-or-more leading single-cell rows. # -> leading single-cell rows are included in subtable # # a -> [ Table(a, b, c, d, e, f) ] # b # c d # e f # -- ❌ CASE 4: There is exactly one trailing single-cell row. # -> core table is dropped. trailing single-cell row is emitted as Title # (this is the behavior in the reported bug) # # a b -> [ Title(e) ] # c d # e # -- ❌ CASE 5: There are two-or-more trailing single-cell rows. # -> core table is dropped. trailing single-cell rows are each emitted as a Title # # a b -> [ Title(e), # c d Title(f) ] # e # f # -- ✅ CASE 6: There are exactly one each leading and trailing single-cell rows. # -> core table is correctly identified, leading and trailing single-cell rows are each # emitted as a Title. # # a -> [ Title(a), # b c Table(b, c, d, e), # d e Title(f) ] # f # -- ✅ CASE 7: There are two leading and one trailing single-cell rows. # -> core table is correctly identified, leading and trailing single-cell rows are each # emitted as a Title. # # a -> [ Title(a), # b Title(b), # c d Table(c, d, e, f), # e f Title(g) ] # g # -- ✅ CASE 8: There are two-or-more leading and trailing single-cell rows. # -> core table is correctly identified, leading and trailing single-cell rows are each # emitted as a Title. # # a -> [ Title(a), # b Title(b), # c d Table(c, d, e, f), # e f Title(g), # g Title(h) ] # h # -- ❌ CASE 9: Single-row subtable, no single-cell rows above or below. # -> First cell is mistakenly emitted as title, remaining cells are dropped. # # a b c -> [ Title(a) ] # -- ❌ CASE 10: Single-row subtable with one leading single-cell row. # -> Leading single-row cell is correctly identified as title, core-table is mis-identified # as a `Title` and truncated. # # a -> [ Title(a), # b c d Title(b) ] ```	2024-02-13 20:29:17 -08:00